1. Field of the Invention
The present invention relates to an illumination device with a low manufacturing cost and having a light emitting element whose durability is not likely to decrease.
2. Description of the Related Art
Japanese Patent Application Laid-Open (Kokai) No. 2008-155751 illustrates an illumination device that utilizes an LED. In the illumination device of this art, a flexible printed circuit board mounted with an LED is stored on an inner side of a case body. The case body includes an oblong cylindrical connector housing portion and is attached to a cover, The flexible printed circuit board is configured by a base portion, a bendable extra length portion, and a card edge connector. The base portion is mounted with the LED, a resistance, a diode, and the like. The extra length portion is provided on the base portion, and the card edge connector is provided on a distal end portion of the extra length portion. In a state with the base portion fixed inside the case body, the extra length portion is bent so as to be arranged and fixed at a predetermined position on the connector housing, so that the card edge connector functions as a connector terminal.
In the illumination device of the Japanese Patent Application Laid-Open (Kokai) No, 2008-155751, a certain strength is required or the base portion and card edge connector of the flexible printed circuit board so as to be reliably fixed to the case body portion and the connector housing, respectively, and further to ensure that the card edge connector does not bend when used as a terminal. However, the extra length portion that connects the connector housing to the case body portion requires flexibility in order to freely dispose the card edge connector inside the connector housing. Therefore, in the flexible printed circuit board of the Japanese Patent Application Laid-Open (Kokai) No, 2008-155751, as shown in FIG. 1, it is necessary to join the base portion and the card edge connector having the same thickness using the extra length portion, which is a separate member having flexibility. However, forming the base portion, the extra length portion, and the card edge connector all as separate joined members leads to an increase in the manufacturing cost of the flexible printed circuit board.
Meanwhile, the base portion of the Japanese Patent Application Laid-Open
(Kokai) No. 2008-155751, which is an LED-mounting board, is generally formed of resin and thus the heat dissipation performance is low. In this board having a low heat dissipation performance, heat can remain trapped in the LED mounted on the board, thus lowering the durability of the LED. Therefore, a higher heat dissipation performance is required for the LED-mounting board.